All bound together: self-assembled symmetric DNA polyhedra were used to organize proteins in 3D space. Biotin moieties were incorporated into the self-assembled symmetric DNA polyhedra. Upon incubation with streptavidin (STV) protein, an STV protein became bound to each polyhedral face, thus resulting in well-structured DNA polyhedra/STV complexes. This strategy was also applied to different 3D DNA nanostructures and different proteins.